We also analysed four available CRCs for recurrent, somatically acquired mutations in known CRC genes by targeted deep sequencing and identified mutations in TP53 in 3/4, APC in 2/4, KRAS in 2/4 and PIK3CA in 1/4 CRC cases, respectively, as possible cooperating events (Table 2). This evidence concerns the gene KRAS and colorectal carcinoma.